Crossbones

EVERYTHING YOU SEE, HEAR OR BELIEVE IS A LIE.
THEY'VE BEEN LYING TO YOU.
ALL OF THEM.

Tamsin and Lark Starling are sister and brother, orphaned when they were young; their parents died fighting in the elite military group known as the Sparrowhawks, a group which ensures the safety and well being of the community they live in and the social structure of their world and most importantly: tracking and hunting down rebel groups which could threaten the government's perfect system.
Groups like: The Crossbones.
Led by a notoriously elusive rebel known as the Black Skeleton, Tamsin and Lark have heard all their lives of how dangerous The Crossbones are and how much of a threat they pose, though they have always secretly held the hope that they would be the ones to defeat this seemingly unbeatable foe and vanquish the group forever to bring glory to their names.
When the Starling siblings are finally accepted into the honorable ranks of the Sparrowhawks they are both eager to begin the hunt that their parents partook in and to finish the unfinished business once and for all in their memory.
However, when their mission turns abruptly into disaster, Tamsin and Lark are thrown headfirst into the explosive world of the Crossbones and into the hands of the infamous Black Skeleton.
But as the Starling's dive deeper into the lives of those within the Crossbones they begin to realize that their intentions are quite different to what they first expected and that they are not at all how they were described.
Tamsin and Lark begin to find out things which if proved true, could change the very world they live in forever.